Year	Number
1996	10.3
1997	7.58
1998	5.67
1999	1.77
2000	5.9
2001	5.6
2002	5.61
2003	3.95
2004	4.5
2005	3.18
2006	3.84
2007	4.87
2008	1.58
2009	4.01
2010	6.88
2011	12.23
2012	12.67
2013	6.85
2014	18.89
2015	6.2
2016	2.98
2017	7.93
2018	3.94
2019	2.72
2020	5.5